Deflection plate



NOV. 20, 1951 PQHLE 2,575,836

DEFLECTION PLATE Filed Aug. 5, 1950 2 SHEETS-SHEET 1 5 INVENTOR.

ERIC POHLE ATTORNEYS Nov. 20, 1951 E. PQHLE nsmc'rxon PLATE 2 SHEETS-Sl-iEE'I' 2 Filed Aug. 3, 1950 IN V EN TOR. (ERIC POHLE Fig. 6

A T TORNE YS Patented Nov. 20, 1951 DEFLECTION PLATE Eric Pohle, Clifton, N. J minor to Allen B. Du Mont Laboratories, Inc., Clifton, N. J a corporation of Delaware Application August 3, 1956, Serial No. 177,371

4 Claims.

This invention relates to cathode ray tubes and more particularly to the deflection plates of electrostatically deflected cathode ray tubes.

One of the principal problems in electron dis-' charge devices is the rigidity of the electrode structure. This is particularly true in cathode ray tubes which have comparatively long slender electron gun structures. Since the deflection plates of electrostatically deflected cathode ray tubes are usually at the very end of the electron gun, they are most susceptible to vibration and shocks. Furthermore, it is necessary to achieve a rigid electron gun structure at the lowest possible cost, which means with the simplest elements and manufacturing processes.

It is an object of this invention to provide an improved cathode ray tube. Other-objects are to provide a rigid and an easily manufactured and inexpensive deflection plate structure. Further objects will be apparent after studying the specifications and the drawings in which:

Figure 1 shows a deflection plate assembly using deflection plates embodying this invention;

Figures 2 and 3 show the deflection plate 01' Figure 1 in a partially completed state;

Figures 4 and 5 show a modified type of deflection plate embodying this invention; and

Figure 6 shows a complete electron gun in a cathode ray tube using the deflection plates shown in Figure 1.

As may be seen in Figure 1, the deflection plates ll, [2, l3, and H are supported from insulating rods l6, l1, l8, and IS. The deflection plate II is secured to the two insulating rods l6 and Il by a pair of turn back clamps 2| and 22 which are formed from the same piece of sheet metal as the rest of the deflection plate II.

In Figure 2 the clamp 2| is shown extended as it is when the deflection plate II is cut from the sheet metal stock; while the clamp 22 is shown in the final form. Figure 3 shows that a stem portion 23 of the clamp 22 is bent back from the deflection plate I l and extends outwardly from the base 24 a distance sufficient to place the C-shaped portion 26 clear of the upper part of the deflection plate 21. A tab 28 extends from the end of the C-shaped portion 26 adjacent to the stem 23. When the deflection plate II is mounted on the insulating rods I6 and I! as shown in Figure l, the clamp 22 is slipped over the end of the rod I1 and the tab 28 is welded to the stem 23 to hold the deflection plate ll securely to the rod [1. The clamp 2i is hooked over the rod l6 in similar fashion and secured thereto.

In Figure 4 the clamps I M "and I22 are shown as part of a piece of sheet metal strap 23 separate from the deflection plate ill. The clamps l2l and I22 are formed from the strap 23, which is then welded to the deflection plate llll. Figure 5 clearly shows the mounting of the strap 29 on the deflection plate Ill.

Figure 6 shows a complete electron gun comprising a control grid 3|, an anode 32, a Iocussing anode 33 and another anode 34, all mounted on a pair of ceramic rods I6 and i8 which are the same as the rods l6 and la in Figure 1. The

' anode 34 is ordinarily connected electrically to the anode 32. A metal disc 36 is attached to the end of anode 32 adjacent the focusing anode 33 and a similar disc 31 is clamped to the end of the anode 34 adjacent the focussing anode 33. These discs 36 and 31 act as corona shields and also as supports for an extra pair of insulating rods I1 and IS. The rod I9 is not visible in Figure 6 since it is directly behind the rod Hi. The rod H is clamped to the discs 36 and 31 by two metal tabs 38 and 39, and the rod I9 is similarly clamped to the discs 36 and 31 by a pair of tabs 4| and 42 which are only partly visible behind the rod l6. In the interest of achieving similarity of the deflection plates, the rods l6, l1, l8 and iii are preferably evenly spaced around the periphery of the discs 36 and 31. Thus the deflection plate clamps such as clamps 2| and 22 on deflection plate II and can all be bent back in exactly the same way for all four of the deflection plates.

While a specific electron gun structure has been illustrated for use with these improved deflection plates, it will be obvious that this invention is not limited by any particular type of electron gun. Other modifications may also be made without departing from the spirit of the invention.

What is claimed is:

1. A cathode ray tube deflection plate comprising a sheet metal plate member, a pair of sheet metal stems extending from one side of said plate member said stems having their outer extremities bent into the form of C-shaped clamps and terminating in tabs, said tabs extending toward said plate member adjacent their respective stems.

2. A cathode ray tube deflection plate structure comprising a pair of parallel insulating rods; a sheet metal plate member, a pair of sheet metal stems cut from said plate member and extending from one side thereof and having their outer extremities bent into the form oi G-shaped 3 clamps terminating in tabs, said tabs extending back toward said plate member adjacent and substantially parallel to their respective stem.

3. A cathode ray tube deflection plate comprising a sheet metal plate member, a sheet metal ribbon attached to one side or said plate with the ends of said ribbon extending substantially perpendicularly-1mm said plate, each or said ends having its outer extremity bent into the form or a C-shaped clamp and terminating in a tab, each oi! said tabs extending normalto said c-shaped clamp and back toward the plate member -adjacent its respective stems.

4. A cathode ray tube electron gun assembly comprising a plurality of tubular electrodes supported by and supporting a plurality of insulating rods, a pair of deflection plates supported by four of said rods, each of said deflection plates comprising a sheet metal plate member, a pairof sheet metal stems extending from one side of said plate member each of said stems having its 4 outer extremity bent into the form 0! a O-shaped clamp terminating in a tab extending normal to said C-shaped clamp, each said clamp surrounding one or said rods with its tab being welded to its stem to eiiect a clamping action by said clamp on. said rod.

. ERIC POHLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,206,413 Malofl July 2, 1940 2,231,146 Wellmann et al. Feb. 11, 1941 2,372,901 Koch et al. Apr. 3, 1945 2,391,273 Rutherford Dec. 18, 1945 2,461,728 Gessford Feb. 15, 1949 2,461,743 Krahl Feb. 15,1949 

